1. Field of the Invention
This invention relates generally to toys or amusement devices for easily drawing a variety of complex, attractive designs; and more particularly to such a toy or amusement device capable of drawing a particular design twice or more, offset by fixed and controllable amounts to produce a compound design.
2. Prior Art
It is known to provide a toy or amusement device, for drawing designs, in which a paper carriage or platform rotates below a pen-holding arm while the arm performs various other motions that are coordinated with the rotation. Of course other drawing media may be substituted for paper, and other drawing implements for a pen.
Such devices usually produce designs made up of lobes repeated in a generally circular array, by virtue of the coordination between carriage rotation and arm motion. In prior devices of which I am aware, the coordination has been provided by a rotating eccentric that drives one end of the arm.
The eccentric is itself belt-driven from the carriage, either directly or indirectly. That is to say, the eccentric and the carriage each either themselves serve as driven and driving pulleys, or carry such pulleys, or are linked with such pulleys.
In such a device the number of lobes per revolution is nominally established by the ratio of diameters of the driven and driving pulleys. In an inexpensive belt-driven device this is very likely to be (or to soon become) an incommensurable number.
In other words, there will not be a rational number of lobes in each design. The pen does not come back around to the same place where it starts, closing the design, but rather continues in a new revolution of the carriage from a new starting point with some uncontrollable offset--which results automatically from operation of the device.
The results are often appealing, and are recognizable as a rotary form of Lissajous figure. The continual migration of the starting point on each rotation, and the resulting ever-denser appearance of the perpetual spiral, are fascinating to a person who has not seen them before.
It is a commonplace observation, however, that a person playing such a device tends to lose interest in it quickly. Here are two probable reasons for this rapid saturation of interest:
First is the nearly complete absence of opportunity for creative contribution by the user or player. Use is limited to continuous operation of the mechanism, to generate whatever pattern turns out to be produced, and to accepting the design as it comes out.
Second is the very fact that there is no stopping point. There is literally "no end to it," and most users probably feel compelled to get off an endless treadmill as soon as they realize they are on it.
In short, playing with such devices is boring and unending--surely a bad combination.